JFR, Berryman's Chemtool Fuel Injector Cleaner is used at 1 oz per gallon.
I tied so far a total of 44 oz (12+32 oz) of Yamalube Ring Free Plus at a bit higher rate than directed (1 oz per 10 gal.). And my last tank I went all-in at 1 oz per gallon (10x more than recommended) which was extreme in some way because my mileage got worsen with 3 miles per gallon. But a VAG guy on here told me he they used it up to 1 oz per gallon and I followed. I didn't got any check engine or anything just bad MPG. But also I didn't fill up the highest octane to I just got 87 which was mistake too.
I didn't do any before/after pics because don't have borescope, but the thing I noticed that my exhaust tip went from balck to light brown and the soot inside disappeared. I just got another 32 oz bottle of the Yamalube Ring Free Plus and will repeat the test, because my exhaust tip became black and sooty right after I stopped suing it. This time I'll take some pictures of my exhaust tip.
But before that, I already have lined up three 12 oz bottles of Valvoline Restore and Protect Fuel System Cleaner to use. I'll report on that too with pics of my exhaust pipe tip as well. I'm planning to use it as directed on the label—12 oz per 18 gallons which in my car will be 3.5 fuel tanks.